RB67 Light leak help needed

VTIMAGEMAKER

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My first roll of film shows a light leak. I replaced all the light seals with the exception of the weird little light trap fuzzy strip in the film back where the slide goes in. I have since worked on that and don't think that will be any problem. I'm looking for an issue on the top portion of the film back or the rotation mechanism. How should I go about troubleshooting?



 

MattKing

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While that might be the result of a light leak, it also looks like what can happen if the film is wrapped too loosely - usually when it comes out of the camera - and then put somewhere where the light sneaks around the edge of the spool.
A so-called "fat roll".
I don't know whether the Catlabs film might be more prone to that then others, but the variation between spools and backing paper stocks when compared to something like Ilford or Kodak or FOMA film could certainly be relevant to the issue.
I remember using some off-brand 120 film during the mid 2000s where the backing paper was so stiff and apparently inflexible that the film was very difficult to handle. Perhaps the problem is similar to that.
You may need to load and unload this film to and from cameras in more subdued light, and may need to protect it more when handling it outside the camera.
 

Rick A

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I think I'm going to have to agree with MattKing on this one.
 
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VTIMAGEMAKER

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Ahhhh. Well that would explain it as it has basically the same form on each frame. I won't be using any of this film anymore and will stick with Tri-x or Plus-x in the future.
 

ags2mikon

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"The bitterness of poor quality remains long after the sweetness of low price is forgotten".
 

MattKing

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VTIMAGEMAKER said:
Ahhhh. Well that would explain it as it has basically the same form on each frame. I won't be using any of this film anymore and will stick with Tri-x or Plus-x in the future.
Click to expand...

I'm not going to disagree with your choice here.
But just so you know, there are films where the qualities of the film make the need to exercise additional care to avoid problems like this is worth it.
For example, the near-IR sensitive films.
 

nostalgix

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Marcelo Paniagua said:
Can you get Plus X? Or is it freezed film?
Click to expand...

Totally off-topic, but I had to laugh, because my heart made a jump when I read the mention of the Plus-X above. I guess I am still not over the loss of that film stock in my life.
 

Donald Qualls

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One of the common sources of fat rolls is a film transport that doesn't keep enough tension on the film. If the film is loose going onto the takeup spool, a fat roll is a likely result. With an RB67 back, check the leaf springs that bear on the rolls on both sides; they should have just a little pressure on and empty spool, which will give them the right level of friction on the backing of a live roll as it transports.

All this to say, the Catlabs film might not be the problem. You'll know if you get another fat roll with your Tri-X or FP4+.
 
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VTIMAGEMAKER

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Exactly. I'll be sending a roll of Portra out and see what happens. I'm going to wrap the film back with electrical tape for a couple of the exposures to see if there is a light leak in the rotating mechanism.
 
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VTIMAGEMAKER

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madhatter said:
Totally off-topic, but I had to laugh, because my heart made a jump when I read the mention of the Plus-X above. I guess I am still not over the loss of that film stock in my life.
Click to expand...

OK,OK I'm old and out of touch. I guess I'll be shooting TriX
 

koraks

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Marcelo Paniagua said:
Yes fat roll issue.
Click to expand...

It's usually worse at either the start or the end of the roll if this is the case.

With a leak at the camera back, it's common to see the problem vary in intensity from frame to frame due to differences in how much light hit upon the leak during use. It's usually possible to tell when someone was shooting in a shaded spot/indoors and when the camera sat unused for an extended period of time.

These are the kinds of clues I generally look for. It usually yields some insights.
 

Donald Qualls

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If you have a bunch of frozen Plus-X you want to dispose of, I can promise it'll be handled responsibly...
 

Codeman73

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Just a bit of a follow up. There are no light leaks in the camera. It was a “fat” roll of film.
 

Donald Qualls

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Glad to hear it. It ought to serve you well -- but be warned, accessories for those can turn into their own version of G.A.S.
 

Codeman73

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Boy, don’t I know it! I’ve picked up some goodies that needed repair like a Pentax spotmeter, a chimney CDS viewfinder and a set of B&W filters. Also a Mamiya aluminum case and a pistol grip all for an incredible $0.99 plus shipping. I really would like to get the 65mm lens one day soon.
 

Rick A

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The "fat roll" issue could be caused by careless handling of the roll of film, allowing it to unspool slightly if you don't keep a tight grip when loading or removing from the back. I wouldn't be in a rush to blame it on the film brand.
 

Eff64

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120 film is tricky. The backing paper does a fairly good job of protection, but it is better to store the rolls someplace dark after shooting. In the years when I used to shoot in the studio, we kept an old cigar box on a table next to the set. As film would be emptied out of the cameras, it would be kept inside the box until it went into the darkroom for processing. Too much risk that stray light would creep past the backing paper on the outer frames.
 

Codeman73

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I’m sure the issue was with how I handled the film and not a manufacturing defect. I did return all the film to CatLabs because it was defective and had small black dots all over the emulsion. They refunded 100% of my order including processing. I will give their management high marks for how my problem was handled. I will not be ordering any more of the X80 film though!
 
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